<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		
		<script>
			"use strict"
			
			// 定义一个点的坐标的构造函数
			function Point(x = 0, y = 0){
				this.x = x
				this.y = y 
			}
			let point = new Point(23, 32)
			console.log(point)
			// 形参的默认值 -- 当不传入参数的时候默认使用形参里的默认值
			let point2 = new Point()
			console.log(point2)
		</script>
	</body>
</html>
